document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1025757>Question 1025757</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The experimental probability of a penny landing on tails is 9/16.  If the penny landed on heads 21 times, how many times was the coin tossed? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #641060 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=641060\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> probability of tails is 9/16.\r<BR>\n" );
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document.write( "therefore the probability of heads is 7/16.\r<BR>\n" );
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document.write( "the penny lands on heads 21 times.\r<BR>\n" );
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document.write( "let x = the number of tosses.\r<BR>\n" );
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document.write( "you get 7/16 * x = 21\r<BR>\n" );
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document.write( "multiply both sides of this eqution by 16/7 to get x = 21 * 16/7\r<BR>\n" );
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document.write( "since 21/7 = 3, you get x = 3 * 16 which is equal to 48.\r<BR>\n" );
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document.write( "the number of tosses is 48.\r<BR>\n" );
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document.write( "21 of those tosses equals heads.\r<BR>\n" );
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document.write( "this means that 27 of those tosses equals tails.\r<BR>\n" );
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document.write( "the probability of tails is therefore 27/48.\r<BR>\n" );
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document.write( "divide numerator and denominator by 3 and you get 9/16.\r<BR>\n" );
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document.write( "that's the probability of getting tails, so the solution is good.\r<BR>\n" );
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document.write( "the number of tosses has to be 48.\r<BR>\n" );
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document.write( "+ </SPAN>\n" );
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